The present invention relates generally to a method and apparatus for counting paper straws. More specifically, the invention relates to a method and apparatus for counting paper straws which have been individually prewrapped.
Paper straws are typically packaged in boxes containing a stated quantity of straws. To ensure that the stated quantity agrees with the actual number of straws in the box, it is necessary to count the straws before they are placed into boxes.
Machines of the prior art intended to be suitable for counting elongated articles such as straws, cigarettes and toothpicks, have typically required the articles to roll easily at some stage during the travel of the articles through the machine. These machines have not, however, been entirely successful in counting paper straws because of the inability of paper straws to roll easily when in contact with one another.
Counting machines of the prior art have generally included a hopper to feed the elongated articles at some stage in the counting process. Paper straws which have been individually wrapped in a paper wrapping are especially difficult to count quickly and easily in a counting machine having a hopper because of the tendency of the paper straws to form an arch within the hopper of the counting machine. The paper straws interact with one another within the arch to prevent each other from coming in contact with a carrier means within the machine.
In a prior art straw-counting machine, a rotary drum is positioned under a hopper. The drum has radial grooves of the proper size to receive two straws. A rotary brush is positioned at the edge of the hopper adjacent the drum to sweep the straws back into the hopper and to assure that only two straws are placed in each groove. A guard is positioned over the lower side of the drum periphery to retain the straws in the grooves as the drum rotates. At the opposite side of the drum, a stripper mechanism is provided to remove the straws from the grooves, allowing them to fall into a hopper where they are collected. A counter indicates the number of revolutions of the drum, and the total number of straws collected in the chamber can be computed from the number of revolutions of the drum. The disadvantage of this machine is that the drum must be rotated slowly enough to ensure that all of the grooves are filled, and there is uncertainty as to the number counted since occasionally a straw may be displaced from the groove just prior to passing under the brush, so that there are inaccuracies in the number of straws counted.
Another example of a similar type of feeding and counting apparatus is disclosed in the patent to Rose, U.S. Pat. No. 1,393,642.
As an example of prior attempts at packaging straws into a wrapping, Goldstein et al, U.S. Pat. No. 1,825,058, discloses a straw-packaging machine which includes a rotary drum with a plurality of radial grooves for receiving straws. Two straws are received in each groove. Loose straws are placed in a hopper and a narrow passage leads from the hopper to the periphery of the drum in alignment with the grooves in the drum. The passage is large enough for the straws to pass through one at a time, and a rotary brush at the bottom of the hopper applies pressure on the straws in the passage to urge them into the grooves in the drum. The straws are then displaced endwise from the grooves to be wrapped in paper and deposited in a separate hopper for packaging. The Goldstein et al patent, however, does not disclose the step of counting the wrapped straws.